Definition of "camphor"

I fancied at first the stuff was paraffin wax, and smashed the jar accordingly. But the odour of camphor was unmistakable. It struck me as singularly odd, that among the universal decay, this volatile substance had chanced to survive, perhaps through many thousand years.

1895 May 7, H[erbert] G[eorge] Wells, chapter X, in The Time Machine: An Invention, New York, N.Y.: Henry Holt and Company